Heating apparatus



Patented Nov. 3, 1936 HEATING APPARATUS William M. Hepburn, OttawaHills, and Theodore W. Mumford, Toledo, Ohio, assignors to SurfaceCombustion Corporation, Toledo, Ohio, a corporation of New YorkApplication January 22, 1936, Serial No. 60,304

6 Claims.

This invention relates to fuel fired radiator tubes for producing heatin furnace chambers and the like. The use of non-gaseous fuels for ringsuch tubes presents special problems that 5 are not encountered whengaseous fuels are used and it is the object cf the invention to -providefor the successful utilization of initially nongaseous fuels and moreparticularly fuel oil for,

, nring such tubes. l Briefly stated the procedure in accordance withthe present invention is as follows: gasifying the fuel by partialcombustion in a chamber in close proximity to the intake end of thetube; conducting the highly heated gases to a point well within theintake end of the tube; supplying a relatively small quantity of air to'the gases at one or more points intermediate the ends of the'con ductorwhereby to insure that the gases shall be burning as they leave theconductor; enveloping the gases where they leave the conductor with thenecessary amount of air to support complete combustion, and inducingsaid air to flow into the tube by draft producing means at the outletend of the tube.

The preferred form of apparatus is shown in theacompa-nying drawingwherein,-

Fig. 1 shows a portion of a heating chamber wall, a radiator tube ofhair-pin type extending through said wall, a cross section of the draft30 producing means associated with the outlet end of the tube, and .aside elevation of the ring means associated with the inlet end of thetube, parts of the tube being in section. Fig. 2 is an enlargedsectional view of the firing apparatus associated with the inlet end ofthe tube.

I0 indicates a radiator tube of hair-pin type and I I a heating chamberwall through which the ends of the tube extend. Associated with theoutlet end of the tube I0 is a draft producing device generallyindicated at I3 and which preferably comprises a discharge nozzle It setto discharge into an eductor tube I5 which forms in effect anextensionvof the outlet end of said tube. Fluid under pressure issupplied to the nozzle by a supply pipe I6 provided with a flowregulating valve I'I. i

I 8 indicates a tunnel type chamber formed by a cylindrical metal shellI Bd having an inner refractory lining I8b. At one end of the cham- 50ber I8 is a device generally indicated at I9 for discharging non-gaseousfuel such as fuel oil in finely divided condition into the chamber I8for partial combustion therein. and 2| indicate supply pipes fordelivering fuel oil and atomizter 22 in front of air inlets 23 ismanually adjustable to regulate the amount of air entering the chamber,it being understood that the amount of air admitted is just enough toeifect partial combustion of thc fuel in order to produce a combustiblegaseous fuel.

The chamber I8 has a circular outlet 24 and l the radiator tube has aflaring inlet 25 which "is open to the atmosphere. The tunnel issupported in axial alinement with the tube inlet in any preferred way asby rigid arms 26 between the rims of the said outlet and inlet.

The gases generated in the combustion cham- 'ber I8 are conducted to apoint well within the inlet end of the radiator tube by a conductorcomprising two disconnected but axially alined tubular members 2l and28. The member 2l is smaller than the member 28 and projects a Shortdistance into the latter whereby to form a relatively short open-endedannular air passage 3G between their adjacent ends; and the member 28 issmaller than the radiator tube whereby to provide an open-ended annularair passage 3| between itself and the tube. The amount of air enteringthe passage 3B is just enough to insure that the gas shall be burningwhen it discharges from the sleeve member 28 whereas the amount of airwhich flows from the passage 3i is enough to support complete combustionof the gas.

The tubular member 2l is desirably so arrangedv with respect to thechamber outlet 2d as to form an open-ended annular passage 29 betweenthe said outlet and. said end. Ordinarly the ilow of fuel into thechamber i8 will be so regulated that for any given setting of the draftproducing means the pressure in the chamber will be only slightly inexcess of the air pressure prevailing around the conduit 21.

The gas which issues from the passage 29 will, of course, burn aroundthe conduit ,21 and thereby give indication that there is a plenum ofgas in the chamber I8. The opening provided by the passage 29 alsomaterially helps in dampening puffing effects in the chamber I8, andperforatons 21 in the conduit 2'I also contribute to the same end.

The member 28 is spaced from the radiator tube I Il by any preferredmeans as by spacing fingers 32. Spacing ngers 33 may also be providedbetween the adjacent ends of said members. The inlet end of the member21 is'vheld concentric with the outlet 24 by any preferred means as byspacing fingers 34carried by aring 35 outside of the outlet at thedischarge side thereof.

Since the air for supporting combustion of the gases flowed into thetube I0 from the chamber I8 is drawn into the tube by draft producingmeans at the outlet end of the tube and the air is caused to surroundthe gas where it is delivered into the tube, it will be readilyappreciated that intermixing of the air and gas proceeds relativelyslowly with the result that combustion proceeds progressively. Localizedor spot heating of the tube is, therefore, prevented and uniform heatdistribution `obtained. At a point intermediate the ends of the tube itis desirable to stir up and thereby accelerate combustion of the flowinggases. In the case of a hair-pin tube the bend between the legs of thetube will cause such stirring to take place as will be readilyappreciated.

The use of means for producing a constant and regulable suction effectat the exhaust end of the radiator tube is essential to proper firing ofthe tube and permits a much greater volume of fuel to be burned thancould be burned if natural draft were relied on to-inducecombustionsupporting air to enter the tube.

Whatwe claim is:

l. The combination with a radiator tube for producing heat in furnacechambers and the like, of means for utilizing initially non-gaseous fuelfor firing said tube comprising: a chamber wherethrough said fuel isflowed for gasification by partial combustion, draft producing means atthe outlet end of said tube for inducing air to enter the inlet endthereof, and a conduit foi` conducting the gases of said partialcombustion to a point well within the inlet end of said tube, the inletend of said tube and the walls of said condutbeing so arranged for airflow whereby the interior of said tube beyond said conduit isopenlyexposed to the inflow of air independently of said conduit andchamber. i

2. The combination with a radiator tube for producing heat in furnacechambers and the like, of means for utilizing initially non-gaseous fuelfor firing said tube comprising: a chamber wherethrough said fuel isflowed for gasification by partial combustion, draft producing means atthe outlet end of said tube for inducing air to enter Y the inlet endthereof, a conduit for conducting the gases of said partial combustionto a point Well within the inlet end of the tube, and means fordirecting a portion of the induced air into said conduit at a pointintermediate the ends thereof, the walls of said conduit and the inneriwalls of said tube being arranged so as to allow air to flow wherebythe interior of said tube beyond said conduit is openly exposed to theinflow of air independently of said conduit and chamber.

3. The combination with a radiator tube for producing heat in furnacechambers and the like. of means for utilizing initially non-gaseous fuelfor firing said tube comprising: a chamber wherethrough' said fuel isflowed for gasification by partial combustion, draft producing means atthe outlet end of said tube for inducing air to enter the inlet endthereof, said inlet end being openly exposed to the admission of airfrom the atmosphere, a conduit for conducting the gases of said partialcombustion to a point well within the inlet end of said tube, saidconduit being exteriorly exposed to the induced air and comprising twopartially telescoped tubular members of different diameters whereby toform an annular space between themselves for the admission of some ofsaid induced air, and the smaller of said members leading from saidchamber.

4. I'he combination ywith a radiator tube for producing heat in furnacechambers and the like, of means for utilizing initially non-gaseous fuelfor firing said tube comprising: a chamber wherethrough said fuel isKfiowed for gasification by partial combustion, draft producing means atthe outlet end of said tube for inducing air to enter the inlet endthereof, a conduit for conducting the gases of said partial combustionto a point well within the inlet end of the tube, and means comprisingan annular passage intermediate the ends of the conduit through which arelatively small portion of the induced air may enter the conduit forsupporting partial combustion of the gasiiowing through the conduit, thesaid inlet end of the tube and the walls of said conduit being soarranged for air flow whereby they i iol openly expose the interior ofthe tube beyond said conduit to the inflow of air from the atmosphereindependently of said conduit and chamber.

5. The combination specified in claim 1, characterized by the inlet endof said conduit being in open communication with said chamber and inspaced relation to the inner walls thereof whereby some of the saidgases may flow out of said chamber around as well as through the saidconduit.

6. The combination specified in claim 3, characterized by the smaller'ofsaid tubular members having apertures in its side walls.

WILLIAM M. HEPBURN. THEODORE W. 'MUNFORD

